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Dave WM

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Dave WM last won the day on January 31

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About Dave WM

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    Central FL
  1. Runs rich, wont rev past 2-3k

    so if you put a brand new plug in it, start it idle for 5 min it comes out black sooty and or wet? trying to find an order of magnitude beyond will not rev. also what plugs are you running?
  2. Runs rich, wont rev past 2-3k

    are the plugs showing as over rich (black sooty) or wet (raw gas).
  3. Runs rich, wont rev past 2-3k

    well lets break it down fuel pressure right AFM seems to check out injectors pulsing Temp sensor resistance matching FSM guidelines compression and timing ok think you said tach seems correct and you have massive over rich conditions based on spark plug readings. Testing everything to the FSM at the 36 pin connector should clear wire harness (some of those pics show a lot of nasty looking corrosion). for EFI issues: I would think maybe bad or wrong ECU or wrong fuel injectors. Trying to test both those (beyond clicking and spraying) is something I don't really know how you would do other tham substitution, which is a costly way of checking things. can you take some pics of the overall engine bay maybe something just being over looked. did you try removing the oil filler cap on the valve cover. A correct setup will run rough and die in a few seconds due to massive ail leak (the PCV system is sealed). only other thing I can think of is the spark actually getting to the plug? wet fuel soaked plugs could be non firing plugs. I assume you have check for spark AT the plugs. doing a power load test or just pulling them all out and looking for spark at this point.
  4. Runs rich, wont rev past 2-3k

    have you tried listening to the fuel injectors with a stethoscope? hear the clicking while running?
  5. Bosal 280-520 for 280z

    I noticed my OE muffler had a leak so decided to tackle replacing it. Only thing I could find that was near OE was a Bosal 280-520. this has a flange that goes from the Catalytic back to the muffler tip. Cheap at only about 50$ with various discounts. 1st thing I noted after pulling the OE was the pipe from the flange back was not as long as the OE before making the bend down the diff. It was about 4" too short. I am guessing that the CAT converter on my CA car maybe short than a standard resonator. Since I don't have a resonator to compare its only a guess. Anyway bought some pipe and various fittings thinking I would fabricate a joiner and use U clamps to connect it all up. After sleeping on it, and think how hokey a bunch of U clamp would look I decide welding was the answer. Now welding is something I have not touched since back in HS shop class back in the 70's and that was arc and gas, but figured it would be fun to try. Got a cheap 170amp HF mig and some gear to go with it, did not have enough gas to try the shielding gas so used the flux wire. Tried a few beads on the scrap pipe I had left over after cutting out the needed joining piece. Wow this is not easy, no granted I prob had everything working against me, cheap welder, flux wire, thin gauge steel , running a bead around a radious, but after a while I was at least getting consistent arcs and wire feed. I unplugged the ECU and put the pieces back on the car, using the big welding magnets to hold in place I managed to get a few tacks in place so I could remove and finish weld. I ringed it with small tack welds and then tried my best to bead it. I prob ground off 90% of my work and would re do until it looked like I had managed a solid unit. I pressure checked it with some soapy water, fixed a few leaks, painted the whole area with some high temp paint and reinstalled. The fitment with the 4.5" added was perfect, too bad I had to add that extension. Exhaust was quieter than before (I would hope all this was done for a purpose) and I know the exhaust gasses are now all coming out of the tail pipe and not from the front of the muffler like before. I clearly need to practice a LOT with the welder but it was fun and a nice learning experience. I cant recommend the BOSAL 280-520 only because I don't know for sure it would fit on a NON CA car, if it did then I would say its a great value. As is its still a good value if you have some welding ability.
  6. 280z power antenna will not go down

    found this keeping it I'm my thread so I can find again easy
  7. Runs rich, wont rev past 2-3k

    the only diff I can see is a voltage drop across the resistor that is between 8 and 9, prob why you were seeing 4v in there some where at one extreme end. Your 8 and 9 is a fixed resistance value. 6 and 8 are the outside legs of the pot, with 7 as the center wiper. Standard test of a pot would be as I described. I guess they wanted to test the fixed resistor as well, but that is a simple resistance test between 8 and 9 (resistance should not change with movement of flap between those pins if I read the schematic right). Lets see what you get when you test like I did.
  8. Runs rich, wont rev past 2-3k

    I redid my test using a 9v battery battery not in circuit 9.5v 6 neg term 8 pos term DMM/analog meter 6 neg lead 7 pos lead flap closed 1.8v sweep shows an increase non linear. I had a momentary 0.00 reading in one spot (right around 6v around 1/3 open) but could never get it to stay. the analog meter duplicated the voltage readings and sweep but was unable to catch the momentary 0.00 (it would only last a fraction of a second). It was consistent as far as happening and happening in approx. the same location of sweep, just could not maintain long enough to diagnose reason. flap fully open 8.5v This is an UNTESTED IN USE AFM so use as comparison only, if your readings are nearly the same I would assume both are good.
  9. Runs rich, wont rev past 2-3k

    I get vary near the same readings resistance as AFM 1
  10. Bringing a 1977 Z back life

    IF yours test bad (no need to replace if ok of course) I suggest you get OE, they are still available and not expensive, generally about 40$ shipped if you shop around. think the aftermarkets maybe 10$ cheaper, does not seem worth the saving IMHO.
  11. Runs rich, wont rev past 2-3k

    well looks like AFM 2 is a problem, I will dig out my spare and see what I get on 7-8 and see if I get the same "small" or near that. I assume that was with the flap in the closed (since 7 is a movable contact). Will get back to you later. AFM 1 is what you have in the car right?
  12. Bringing a 1977 Z back life

    anytime the car is having problems starting, its a good idea to check the starter switch. Its easy to get out, pull it sit down with a continuity checker and go thru the terminals flow the FSM and check function esp full range of the "start" turn. Take this advice from someone that intermittent start issues for a year before doing that. Since its replacement it starts perfect every time.
  13. Runs rich, wont rev past 2-3k

    BTW the go to problem for everyone that 1st starts in on EFI is messing with the AFM, these test will hopefully clear that as a major problem. Frankly I would bet its NOT the problem, just something else overlooked. this is what ZH was talking about, you need to read the fuel pressure at static no vacuum (36 psi), idle (30psi), the ohms from the temp sensor and what temp the coolant is, compare to the table. I just don't want you to overlook anything, the hard numbers will help reassure those trying to help that you are not missing anything. I see no reason not to swap another AFM if you have it just to see if there is any change. hopefully that will be it, but again its prob not unless it has been seriously monkeyed with. who knows it could just be a massive injector leak, a fuel pressure test after shut down will show that, it should hold and least for a few minutes. If the pressure goes away INSTANTLY then clearly a leak, also the FPR's have been know to leak, pull the vacuum line and see if its dripping. seems like it would have to be massive for the kind of problems you are having.
  14. Runs rich, wont rev past 2-3k

    try battery voltage at 6 and 8, then read from 6 and 7 and sweep. you should see a lower voltage as you approach 6 and a ramp up as you approach 8. again absolutes are not what you are looking for just a relatively smooth ramp go slow since you have digital. there are fixed resistors in there that make voltage division with out any sweep. see if you get the same results on the other AFM's. if that seems smooth then that clears the trace of any opens, just compare the fixed resistance readings on 6 to 8 and 8 to 9 between all the AFMs. compare the "feel" of the flap spring resistance of all the AFM's are then about the same?
  15. Runs rich, wont rev past 2-3k

    don't get too hung up on the absolute voltage readings. I was just looking for breaks or large deviations while sweeping the trace. you just want the voltage setup on the lowest and the highest part part of the trace then check the voltage by reading one end of the trace and the center wiper. As you sweep you should see the voltage ramp up as you approach the end of the trace. if you have other AFM just repeat your setup and see if they all behave about the same.